A method for driving a foundation element into the earth by means of vibration

ABSTRACT

A method for driving a foundation element into the earth by means of vibration. According to the invention at least one perforated supporting member is taken along by the foundation element when this element is vibrated into the earth. This perforated supporting member may be a perforated plate or a grid composed of upstanding partitions.

United States Patent Van Weele 451 July 18, 1972 [5 METHOD FOR DRIVING A[56] References Cited FOUNDATION ELEMENT INTO THE UNITED STATES PATENTSEARTH BY MEANS OF VIBRATION 3,416,322 12/1968 Bodme ..173/49 x lnvemorrAbraham Francois Van Week, Waddinx- 2,846,852 8/1968 Cappel ..61/53veen, Netherlands 3,210,897 10/1965 Whittington ..6l/53.6 x

[73] Assignee aw as: FOREIGN PATENTS OR APPLICATIONS 1 185,752 1956Austria ..6l/53 [22] Elm 1970 641,496 1962 ltaly..... 211 App]. No.:28,709 4,648 1920 Netherlands ..61/53 Primary Examiner-Jacob Shapiro[30] Foreign Appumuon Monty Data Attorney-Waters, Roditi, Schwartz &Nissen April 22, 1969 Netherlands ..6906153 57 ABSTRACT 52 U.S. c1..61/53.5, 5274033154536, A method for driving a foundation element intothe earth by [51] Int Cl Emd 7/18 502d 3/l'2 means of vibration.According to the invention at least one ..61 53. 3, 53.6, 50, 36,Perfolrated supPmmg member aken 81mgbY fmmda' [58] of Search I 5 5 tionelement when this element is vibrated into the earth. This perforatedsupporting member may be a perforated plate or a grid composed ofupstanding partitions.

3 Claims, 1 Drawing Figure BACKGROUND OF THE INVENTION The inventionrelates to a method for driving a foundation element into the earth bymeans of vibration; as well as to a supporting member for thisfoundation element.

A foundation element may only be driven into the earth by means of avibrator when the cross-section of this element is rather small. It is,for example, possible to vibrate a metal pile having an I-I-shapedcross-section into the earth. However, such a pile has only a smalllower bearing surface so that its supporting capacity will have to besubstantially derived from the friction between its upstanding sidesurface and the earth. When the upper layers of the earth insufficientlycontribute to this friction, foundation piles which are adapted to bevibrated into the earth due to their small cross-section, can onlyaccept a small load. In case the upper layers of the earth are subjectto subsidence e.g. because the ground level has previously been raised,the friction between the earth and the upstanding side surface of thefoundation element would even act on the element in a downwarddirection, which makes the application of foundation piles which areadapted to be vibrated into the earth wholly impossible.

SUMMARY OF THE INVENTION It is a first object of the present inventionto provide a method for driving a foundation element into the earth bymeans of vibration, wherein the ultimate supporting capacity of thefoundation element is considerably increased.

For this purpose, the method according to the invention is characterizedin that at least one perforated supporting member is carried along bythe foundation element when this element is vibrated into the earth.

Due to the fact, that the (or each) supporting member which is driveninto the earth together with the foundation element is perforated, onlya small resistance will be encountered as the earth may penetratethrough the perforations. Thus, the vibrator will be able to overcomethis resistance even when the overall surface of the perforatedsupporting member(s) is large. Therefore, the perforated supportingmember(s) may be driven into a bearing layer of the earth without anydifficulty.

If the perforations in the supporting member are arranged anddimensioned in such manner that, when the foundation element issubjected to a static load, a bridging effect is obtained in the earthwithin these perforations which is sufficient to transfer the forces tothe supporting member, this supporting member will conduct itself as ifno perforations are present.

If, however, this bridging effect does not occur to a sufficient degreea hardening fluid may be injected underneath at least one perforatedsupporting member.

According to a further aspect of the invention, a perforated supportingmember may be positioned underneath the foundation element before thiselement is vibrated into the earth.

Contrary to the well known non-perforated pile shoes which cannot bevibrated into the earth as the resistance defined by their cross-sectionwould be prohibitive, the perforated supporting member may be easilyvibrated into the earth.

The invention further relates to a supporting member for a foundationelement adapted to be used in the method hereinbefore described.

This supporting member may consist of a perforated plate or of a gridcomposed of upstanding partitions.

The invention also relates to a foundation comprising at least onefoundation element which has been driven into the earth by means ofvibration according to the method hereinbefore described.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be furtherelucidated with reference to the drawing, which shows a perspective viewof the lower portion of a pile provided with two perforated supportingmembers.

DESCRIPTION OF A PREFERRED EMBODIMENT The pile 1 shown in the drawing byway of example is made of metal and is I-I-shaped in cross-section. Apile shoe which is positioned underneath the lower end of this pile 1consists of a grid 2 composed of upstanding partitions. The grid 2 maybe connected to the lower end of the pile 1.

A second grid 2' which is similar to the grid 2 is fixedly connected tothe pile 1 at a distance above the grid 2.

The surface of the grids 2, 2' is large relative to the crosssection ofthe pile 1. Further, the openings of the grids 2, 2' cover at leastpercent of their overall surface.

The pile 1, together with the grids 2, 2' may be driven into the earthby means of a vibrator 3. As the earth may penetrate through theopenings in the grids 2, 2' only a small displacement of the earth willbe necessary during this driving operation so that only a smallresistance will be encountered. After the pile 1 has reached itsrequired depth in the earth, the grids 2, 2 act as supporting members.

The openings in the grids 2, 2' may be arranged and dimensioned in suchmanner that under the influence of a static load on the pile 1 abridging effect will occur in the earth within these openings which issufficient to transmit the forces onto the grids 2, 2. These grids 2, 2will then substantially act as solid plate members.

Further, it is possible to inject a hardening fluid into the earthunderneath the grid 2 and/or the earth below the grid 2' in order toobtain the required supporting capacity of the grids 2, 2. After thepile 1 has been vibrated into the ground to its predetermined depth bythe action of vibrator 3, the hardening fluid is injected through theupper ends of pipes 4 and 4. The lower end of pipe 4 extends through theperforations of lower grid 2, whereas the pipe 4' extends only throughgrid 2' so as to allow for the injection of the hardening fluid, undersuitable pressure, underneath either one or both of the grids.

According to a modified embodiment, the supporting members may consistof perforated plates.

If only one supporting member is used, this member will generally bepositioned underneath the pile so as to act as a pile shoe. Of course,the number of the supporting members may be varied at will in dependenceon the conditions of the earth or the required load capacity of thepile.

The invention is not restricted to the embodiment shown in the drawingwhich may be varied in several ways within the scope of the appendedclaims.

I claim:

1. A method for driving a foundation element into the earth by means ofvibration, comprising, mounting the lower end of the foundation elementon the upper surface of a perforated supporting member, and concurrentlyvibrating the foundation element and said supporting member into theearth, forming said perforated supporting member as a relatively flatelement with upstanding partitions forming a substantially uniform gridover its entire extent with openings which constitute at least 80percent of the entire surface area, whereby the openings are so arrangedand dimensioned so as to provide a bridging effect in the earth throughsaid openings upon subjecting the foundation element to a static loadand render the supporting member equivalent to an unperforatedsupporting member, said supporting member being formed to extendsubstantially beyond the periphery of the foundation element.

2. A method for driving a foundation element into the earth by means ofvibration, comprising; connecting a perforated supporting member to thelower end of the foundation element, the supporting member extendingbeyond the periphery of the foundation element, concurrently vibratingthe foundation element and said supporting member into the earth, andinjecting a hardening fluid into the earth underneath said perforatedsupporting member.

porting members in conjunction with the foundation element into theearth, and injecting a hardening fluid into the earth underneath atleast one of said perforated supporting members.

1. A method for driving a foundation element into the earth by means ofvibration, comprising, mounting the lower end of the foundation elementon the upper surface of a perforated supporting member, and concurrentlyvibrating the foundation element and said supporting member into theearth, forming said perforated supporting member as a relatively flatelement with upstanding partitions forming a substantially uniform gridovEr its entire extent with openings which constitute at least 80percent of the entire surface area, whereby the openings are so arrangedand dimensioned so as to provide a bridging effect in the earth throughsaid openings upon subjecting the foundation element to a static loadand render the supporting member equivalent to an unperforatedsupporting member, said supporting member being formed to extendsubstantially beyond the periphery of the foundation element.
 2. Amethod for driving a foundation element into the earth by means ofvibration, comprising; connecting a perforated supporting member to thelower end of the foundation element, the supporting member extendingbeyond the periphery of the foundation element, concurrently vibratingthe foundation element and said supporting member into the earth, andinjecting a hardening fluid into the earth underneath said perforatedsupporting member.
 3. A method for driving a foundation element into theearth by means of vibration, comprising; connecting a perforatedsupporting member to the lower end of the foundation element, connectingat least one further perforated supporting member to the foundationelement at a distance above the lower end of said element, concurrentlyvibrating said supporting members in conjunction with the foundationelement into the earth, and injecting a hardening fluid into the earthunderneath at least one of said perforated supporting members.